simulate: Simulate stock-and-flow model

In sdbuildR: Easily Build, Simulate, and Visualise Stock-and-Flow Models

Simulate stock-and-flow model

Description

Simulate a stock-and-flow model with simulation specifications defined by sim_specs(). If sim_specs(language = "julia"), the Julia environment will first be set up with use_julia(). If any problems are detected by debugger(), the model cannot be simulated.

Usage

simulate(
  sfm,
  keep_nonnegative_flow = TRUE,
  keep_nonnegative_stock = FALSE,
  keep_unit = TRUE,
  only_stocks = TRUE,
  verbose = FALSE,
  ...
)

Arguments

sfm	Stock-and-flow model, object of class sdbuildR_xmile.
keep_nonnegative_flow	If TRUE, keeps original non-negativity setting of flows. Defaults to TRUE.
keep_nonnegative_stock	If TRUE, keeps original non-negativity setting of stocks Defaults to FALSE.
keep_unit	If TRUE, keeps units of variables. Defaults to TRUE.
only_stocks	If TRUE, only return stocks in output, discarding flows and auxiliaries. If FALSE, flows and auxiliaries are saved, which slows down the simulation. Defaults to FALSE.
verbose	If TRUE, print duration of simulation. Defaults to FALSE.
...	Optional arguments

Value

Object of class sdbuildR_sim, a list containing:

df

Data frame: simulation results (time, variable, value)

init

Named vector: initial stock values

constants

Named vector: constant parameters

script

Character: generated simulation code (R or Julia)

duration

Numeric: simulation time in seconds

success

Logical: TRUE if completed without errors

...

Other parameters passed to simulate

Use as.data.frame() to extract results, plot() to visualize.

See Also

build(), xmile(), debugger(), sim_specs(), use_julia()

Examples

sfm <- xmile("SIR")
sim <- simulate(sfm)
plot(sim)

# Obtain all model variables
sim <- simulate(sfm, only_stocks = FALSE)
plot(sim, add_constants = TRUE)


# Use Julia for models with units
sfm <- sim_specs(xmile("coffee_cup"), language = "Julia")
sim <- simulate(sfm)
plot(sim)

# Close Julia session
use_julia(stop = TRUE)

sdbuildR documentation built on Nov. 19, 2025, 5:07 p.m.